Lightning arrester



Patented Feb. l2, 1924.

UNlTEQsra'rsrarenr OFFICE.

cHEsTER'm. ALrloU'r'r, or rrr'r'sBoaeH',` raNNsYLvANIA, AssIeNo'r fro'wr'is'iinierrooss ELECTRIC e MANUFACTURING oorarANra eonronarrron or PENNsYLvANIa Application tiled May 6,

To all whom, t may concern.:

Beit :known that I, CHESTER T. ALLCUTT, a citizenfol the United States, and a resident of'PittslJurgh. in the county ot Allegheny and rState'of Pennsylvania, have invented a new 'and useful improvement in Lightning Arresters; of `which the following is a specification. l

y My invention relates to'lightning arresters" and it hasv particular relation to appa- 3 ratus offthe chaiacter,desigiiated wherein two* electrodescomposed ot conducting material .arespaced apartby means ot a. `dis.- chargexhlock composed of particles of conducting and noniconductinLr materials.

The object of my invention is to provide anV arrester yotl the character indicated whereinl an'yf discharge of currentl through the `block vcaused hy a voltage slightly above the'r normal `will he allowed to passy to v groundavithout, in any Way, permanently v f y haige blockA ail'eoting the arrester and 'wherein any `excessiveor prolonged discharge of current caused by 'ahveryhigh ,potential being impressed on :the arrester will automatically increasethe resistance thereof to`ar point which renders continuousv How of current through the establishedr path impossible, ythereby causi'n the discharge to seek a new path, provider the voltage is still above normal o 'V Heretofore7 it has been suggested to place a block ot carbon or similar retract/'ary' con ducting material 'between two 'plateelectrode's and to place a liller of lead peroxid betii'een the carbon and the electrodes. The electrodes are each providedA with an' insu rloting` film on the side' adjacent the lead Iieroxidiivhich prevents continuous passage ofy current therethrough when a difference otpotential lexists hetaveenjthe two elec trodes. "y 1 i, By'lny invention` I provide an arrester in which the carhoii block is replaced hva disformcd ot particles of conductin;` material held in invariable but, spaced nrelation hy means of particles ot noufconductingmaterial, thereby' eliminating the necessity oi' the insulhting film and improv- .ing:the'protection afforded hy the arrester` 'theaccompanjlfing drawing, l show an .arrester provided with a conducting plate or relectrodc l connected to asupply circuit lrthrougzh a spark gap 3, and .a similar conducting yplateor electrode 4 spaced therefrom f LIGHTNING AaaEsrrnR. I

1919, serial No. assise.

i and connected to ground at li. The plates particles ot conducting and non-conducting material, the conoucting particles, such for example as carhorundum, being held 'in .in-

variable, out spaced, yrelation by means ot the non-conducting particles. Intermediate the conducting plates and the ldiechange block 6 are disposed layers 7' of lead peroxid or some similar material which is normally of low resistance and is converted by heat' intoa material ot' relatively high. resistance. f d

In an arrester `oilthjis type, any smell dis-- charge of current of short duration caused. oy a slightly abnormal potential will pass through the lead peroxid and through the discharge blocks to ground withoutproduc ing an appreciable increase in'ternpc'rature thereo, on account of 4the cooling effect of the discharge block; llIorveve-rik should a large c rrent pass throiigh .the arrester caused hy a very high potential heine; im pressed on the supply circuit to which it vvis connected, the discharge block will skilled in the art that a discharge bloeit of o the character described will prevent any continuous discharge therethrough at normal Voltage and that, if vthe discharge bloeitL contains any imperfection whereby a con`- tinuous path for current or a path of andesirahle low resist-ance is provided through the block, the action of the lead peroxid will permanently seal this path, thereby rester ing' the arrester to its desired condition.

Also,a discharge hloclr of the character described possesses the inherent property of heiner substantially non-conductingto our rents of normal voltage, ot relatively great resistivity to currents having a voltage slightlyv above normal, and ot relatively smallresistivity to currents hai/ine an eX- cessi've voltage. Thist'act aids in preventying" any chen e in the lead peroxid ,when current causeil by a slightly abnormal yvoltage passes through the arrester and in cans inlg a permanent change in the lead pcroxid W en a. current caused by an excessively hi h voltage obtains.

iile lhave shown but one form of my invention and described in detail only one application of the same, it will be understood by those skilled in the art that it is not so limited but is susceptible of various minor changes and modifications without, departing from the spirit thereof, 'and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or are specifically set forth in the appended claims.

I claim as my invention:

l. An electrical discharge device comprising a plurality of spaced conducting menibers, means disposed intermediate said niembers embodyin interiningled particles ot' conducting an insulating material and a layer embodying a metal compound which becomes converted by heat into a compound of high resistance.

2. An electrical discharge device comprising a plurality of spaced conducting members, means disposed intermediate said meinbers embodying a layer of interiningled particles of conducting and insulating niaterial, the conducting particles being held in a substantially invariable relation but out of contact With each other and a layer embodying a conductive oXid which becomes converted by heat into a diti'erent oxid ot' higher electrical resistance.

3. An electrical discharge'devicc comprising a plurality of spaced conducting members, means disposed intermediate said members embodying a layer of interminglcd particles of conducting and insulating material, the conducting particles being held in asnbstantially invariable relation but out of Contact `aiith each other, and a layer of a metal compound of low heat conductivity and low electrical resistance which becomes converted by heat into a compound of diii erent chemical composition and high electrical resistance.

4. An electrical discharge device comprising a plurality of spaced conducting members, means disposed intermediate said members embodying a layer of intermingled particles of conducting and insulating material, the conducting particles being held in a substantially invariable relation but out of contact wth each other, and a layer of lead peroxid 5. A lightning arrester comprising two conducting plates each provided with a coating of lead peroxid and spaced apart by means of a block embodying a mixture of conducting and non-conducting particles, the conductin particles being held in invariable relation but out ofcontact with each other by the non-conducting particles.

6. A lightning arrester comprising two spaced conducting plates, one of which is connected to a source of clcctromotivc l'orcc and thc other of which is connected to ground. a body composed ot interininglcd particles ot' condiufting and insulatingY material disposed internualiatc said plates, and a layer of lead pcroxid dispofcd intcrmediate cath of said plates and said body of commingled particles.

7. An clcclrical discharge dcvicc comprising a plurality of spaced electrodes. means disposed intermediate said clccirodcs cmbodying a body of material thc conductivity ol which increases willi an increase of voltage and a layer ot' conductive oxid which becomes converted by heat into a dill'ercnt oxid ot' higher electrical resistance.

8. An elect rical discharge device comprising a plurality of spaced electrodes. means disposed intermediate said electrodes comprising a body of material the conductivity of which increases with an iicrcasc of voltage, and a layer of a metal compound which becomes converted by heat into a salt of high resistance. f

9. An electrical discharge device comprising a plurality of spaced electrodes certain ot' which are connected to a supply circuit, means disposed intermediate said electrodes comprising a body of material which is substantially non-conductive at normal voltage of said supply circuit; and the conductivity of which increases with an increase of voltage thereof and a layer of a metal compound which becomes converted by heat into a compound of high resistance disposed intermediate said body and said electrodes.

10. An electrical discharge device, comprising a plurality of spaced electrodes certain offwhich are connected to a supply circuit, means disposed intermediate said electrodes comprising a body of material the conductivity of which increases with an increase of voltage of said circuit, and a layer of lead peroxid.

11. An electrical discharge device comprising a plurality of spaced electrodes one of which is connected to a supply circuit, means disposed intermediate said electrodes comprising a body of material which is sub stantially non-conductive at the normal voltage of said circuit and the conductivity of which increases with au increase. of voltage thereof, and a layer of lcad pcroxid disposed intermediate said body and said electrodes.

'12. A lightnin electrodes, one o which is connected to a supply circuit, a pluralit of current paths extending therebetween tie conductance of which is substantially nil at normal potential of said circuit and which varies in direct relation with excessive potentials impressed thereon and in inverse relation to the current passing through said nrrestlg.

arrester cpmprisin;T twoA 13. A lightning arrester comprisin two electrodes, one of which is connecte to a supply circuit, said electrodesbeing s aced apart by bodies composed of different inds -of material, the conductance .of one of said materials (varying directly with the voltage impressed on the circuit and the conductance of the other of said materials varying inversely with current passing through the arrester.

14:. A. lightnin arrestercomprisng two electrodes, one o? which is connected lto a supply circuit, said electrodes being spaced apart by bodies composed of different kinds varying in direct relation with of material, the conductance of one of said materials being substantially nil at the normal potential of said supply circuit and the impressed potential thereof and the resistivity of the other of said materials being substantially nil for relatively small currents passing through said arrester and varying in direct relation with relatively large currents passing therethrough.

Ini testimony whereof, I have hereunto subscribed my naine this 24th day of April, 10191 CHESTER T, ALLCUTT, v 

